Platinum-Nickel/L-zeolite Bimetallic Catalysts: Effect of Sulfur Exposure on Metal Particle Size and n-Hexane Aromatization Activity and Selectivity

Experimental evidence that Ni can be used to stablizie Pt particles supported in L-zeolite against deactivation by sulfur is presented. A series of Pt-Ni/L-zeolite bimetallic catalysts prepared by co-impregnation were tested for n-hexane aromatization and characterized by Extended X-ray Absorption Fine Structure (EXAFS), hydrogen chemisorption and Transmission Electron Microscopy (TEM) before and after sulfiding. It was found that bimetallic particles are significantly less subject of sulfur-induced particle growth than their monometallic (pt) counterpart. This mechanism of catalyst fouling is known to cause deterioration of Pt/L aromatization catalysts.